With the rapid development of communication networks, there are more service types, such as mobile, voice, video, online game, and Internet browsing, and a larger bandwidth is required. To transmit a service such as a time division multiplexing service, complicated service classification must be performed on a communication network, and a processing process of a switching device must be simplified as much as possible, so as to improve processing efficiency and quality of the switching device.
FIG. 1 is a schematic diagram of a switching apparatus for an optical channel data unit (ODU) of a time division multiplexing service in the prior art. The switching apparatus of the ODU performs switching based on cells and includes an ODU service receiving line card, a cell switching unit, and an ODU service sending line card. The ODU service receiving line card further includes a demapping unit and an interface control unit. The ODU service receiving line card extracts bit stream data of a payload from a received ODU service by using the demapping unit; the interface control unit is configured to encapsulate the extracted bit stream data of the payload into a time division multiplexing cell frame, where an identifier of the ODU service sending line card is carried in overheads of the time division multiplexing cell frame. The cell switching unit sends the time division multiplexing cell frame to the ODU service sending line card corresponding to the identifier according to the identifier of the ODU service sending line card carried in the overheads of the time division multiplexing cell frame. The service sending line card further includes an interface control unit and a mapping unit. The interface control unit is configured to extract a payload of the received time division multiplexing cell frame to generate a bit stream of a cell. The mapping unit uses a byte interleaving manner to recover the ODU of the time division multiplexing service according to configurations on a network management system.
In the prior art, forwarding based on Ethernet switching cannot be performed on an optical channel data unit ODU of a time division multiplexing service, which reduces compatibility of a device.